Sorry, you cannot charge your Model 3 for free
Tesla has supercharging stations all over the United States and they are increasing the number of these stations each year. However, the best part of these stations was that you don’t need to pay to charge your Model S or X but the same thing does not apply to Model 3.
Tesla Model 3 costs $35.000 which is way cheaper than the Model S or X. However, there is one handicap of this price. You will need to pay money to charge your Model 3 in the supercharging stations unless you buy “that package” Surprise!
Obviously, [free Supercharging] fundamentally has a cost. […] The obvious thing to do is decouple that from the cost of the Model 3. So it will still be very cheap, and far cheaper than gasoline, to drive long-distance with the Model 3, but it will not be free long distance for life unless you purchase that package. I wish we could, but in order to achieve the economics, it has to be something like that.”
Source – TheVerge